1. Field of the Invention
The present invention relates to a heavy duty plastic hollow board and a mold assembly for manufacturing the same. More particularly, the hollow board is characterized by an integrally sealed exterior which contains an enclosed space with a plurality of strengthening ribs therein.
2. Description of Related Art
Plastic board is a material providing extensive usages. Generally, in prior arts (as shown in FIG. 1), for reducing the weight, advancing the structural strength and increasing the load capacity of a plastic board with a determined thickness, a plurality of fillisters may be applied on either major surface of the board. The spaced fillisters substantially facilitate reducing the weight of the entire board and relatively define protruding ribs which contribute to the structural strength and load capacity thereof. However, the resultant corrugated surface is, not exteriorly aesthetic in a way and consequently, the opposite plane surface thereof is usually taken as the only applicable surface. Such a limit of application is disadvantageous and uneconomical. Thus, a need exists for a plastic board with an integrally even exterior and the advantages of light weight, firm structure as well as heavy load simultaneously. It may be accomplished through a structure consisting of an integrated surface and an enclosed space with a plurality of strengthening ribs contained therein, yet such an optimal plastic board is not achievable by means of conventional one-piece-forming technique.